For example, JP 2000-280917 A (Reference 1), regarding “a steering position adjusting control device that changes a position of a steering wheel in an up-down or front-rear direction” (described in paragraph [0002] in Reference 1), discloses, as a mechanism that “makes a change in a front-rear direction,” “a telescopic mechanism, that is, a mechanism that moves a moving column with respect to a fixed column in a front-rear direction in a steering position adjusting device” (described in paragraph [0004] in the same, but, drawing reference numerals are omitted). Then, regarding an embodiment thereof, it is described that “by constantly pressing a radial backlash preventing bushing downward toward a moving column due to a biasing force of a disc spring, the backlash in the radial direction between the moving column and a fixed column is eliminated” (described in paragraph [0018] in the same, but, drawing numbers and drawing reference numerals are omitted).
JP 2013-067313 A (Reference 2) suggests “a steering device of a vehicle which is capable of adjusting at least a steering wheel operation position in a front-rear direction of a vehicle body, that is, a steering device in which a unit of restricting an axial movement of a movable column member with respect to a main housing may be constituted by a small number of parts at a low cost” (described in paragraph [0007] in Reference 2). Then, regarding an embodiment thereof, it is described that “a biasing member of the embodiment includes a steel substrate fixed to end faces of a pair of side wall portions, and a pair of spring members which bias an outer tube toward a bush at positions spaced apart from each other by a predetermined distance in the axial direction with respect to a planar portion of the outer tube. The spring member in the embodiment is formed by stacking a plurality of disc springs, and is arranged so as to press the planar portion of the outer tube via an abutment member made of a synthetic resin and supported by the substrate, and then is fixed to a main housing, thereby applying a desired pressing force to the outer tube” (described in the same paragraph [0031], but, drawing reference numerals are omitted).
By the “radial backlash preventing bushing” described in Reference 1 above or the “biasing member” described in Reference 2 above, a pressing load is applied to the “moving column” or the “outer tube” (both correspond to a “column tube” of this disclosure), and thus a backlash of the column tube in the radial direction may be prevented. However, depending on the structure, the pressing load may be concentrated on the column tube, and it may be difficult to achieve compatibility between securing of sliding property and prevention of backlash of the column tube. With respect to the concentrated load, it becomes necessary, for example, to perform a coating process or the like on the column tube in order to ensure the sliding property while preventing the backlash, thereby causing a cost increase.
Thus, a need exists for a steering device which is not susceptible to the drawback mentioned above. The “fixed column” described in Reference 1 above and the “main housing” described in Reference 2 above correspond to a “column housing” of this disclosure, and the “radial backlash preventing bushing” and the “biasing member” are also called a “telescopic tensioner,” but this disclosure uses a “pressing mechanism”.